Measuring instrument.



W. C. MACKINNON. I MEASURING INSTRUMENT.

APPLICATION FILED IuLY 23.I9o1.

W. C. IVIAcKlNNON.

MEASURING INSTRUMENT.

APPLICATION min JULY 23, 1 907.

112116111111 Nov. 16, 1915.

2 SHEETS-SHEET 2.

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MEASURING INSTRUMENT.

Specication of Letters-Patent.

- ratenteanwie, raie.

Application led July 23, 1907. Serial No. 385,162.

To all 'whom 'it may concern:v Be it known that I, WILLIAM C. MACKIN-NoN, a citizen of the United States, and a resident of West Orange, inthe county of 'Essex and State ofNew Jersey, have invented certain newand useful Tmprovements in Measuring Instruments, of which the followingis a description.

'My invention relates to measuring instruments, and more particularly tosurface or depth gages, and consists in parts, improvements andcombinations herein set forth and claimed.

In order that my invention may be clearly understood, reference ishereby made to the accompanying drawings wherein the .same referencenumerals .are used to indicate the same parts throughout, and inwhich.-v

Figure 1 is a front elevation of one form of my invention, the improvedgage being shown in this figure as arranged for use as a depth gage.Some parts are broken away in this view to show the details ofconstruction ;l Fig. 2 is a rear elevation on a larger scale of the dialcasing with its back removed, certain of the parts being vbroken awayand others shown in section for greater clearness; Fig. 3 is across-sectional View, taken on line 3- -3 of Fig. 2; Fig.` 4 is a bottomplan view of the device shown in Fig. 1, and Fig. 5 is an elevationalview ofy my improved measuring instrument mounted for use as a surfacegage.

The casing 1 comprises a cylindrical ring 2 formed with an outwardprojection 3 in which is secured the sleeve 4 which, as shown in Fig. 1,is graduated for the rough or preliminary measurement. In the deviceillustrated, the sub-divisions of this sleeve are formed at 'each .2, ofan inch, and it is provided with peripherical grooves at each such pointof sub-division. A chuck 5 is pro vided with spring jaws 6, which can beclamped in place within the aforesaid. subdividing grooves by means of aclamping sleeve 7. This chuck 5 is screwed into a suitable straight edge8 within screw threaded apertures 9, 9 therein, one such aperture beingshown at the middle vof the sald straight edge, and one near the endthereof,

in order that the device may be used in measuring the depth ofholesformed close to a Wall. Extensions 10, 10 of the orifices 9 areprovided, through which the sleeve 4 may extend. Within the longitudinalcavity'of the sleeve 4 is Va measuring rod 11, which normally projectsbeyond the end of the sleeve for a distance which is preferably equal to-one of the subdivisions of the sleeve or, in the device illustrated, .2of an inch. The opposite end of the measuring rod 11 extends through anorifice 12 within the cas ing ring 2, and is provided Within the saidcasing with a cross head 13, whichis provided with a screw threadedorifice 14 to receive the threaded end of the said measuring rod 11.This cross head is preferably split longitudinally as is shown at 15,and is provided with a screw 16 for clamping it upon the rod 11. By thismeans the rod may be adjusted within the cross head and secured at anydesired pointy of adjustment. A sprin 17 interposed between the innerwall of t e ring 2 and the cross head 13 and held in place, for example,by studs 18 and 19, serves to project the rod 11 from the casing 1 andthe sleeve 4. A stop 20, which is formed of material of a somewhatresili' the pointer 27. 'The rear trunnion on this Shaft, indicated bythe reference numeral 28, has a bearing in a bar 29 suitably securedwithin the casing, as for example by means of a screw 30, by which it isheld in place in a block 31,'secured either to the front plate 24 of thecasing or to the ring 2, or to both, as may be deemed desirable. A dowel32 may be used if desired, to accurately position the said bearing arm29. The dial 33, which is preferably provided with central opening 34,is placed upon the plate 24, and is provided with suitable graduations,as shown in Fig. 1. This dial and pointer 27 are covered by a glass 35,which is held at a suitable distance from the dial by means of a ring36.

The dial, which is preferably formed of a resilient'material, is formedwith a flange 37 which fits within a recess 38 within the ring 2, andthis flange is preferably spun or turned up upon the glass 35,v as shownat 39, and is again flanged outwardly as shown at 40, the margin ofV`the last named flange -being preferably provided with a knurled edge41, by which the dial may be turned bodily within the casing. The ring2, at the outer beveled edge of the recess 38, is spun inward slightlyat 42 so as to retain the dial in place therein, but not with suicienttight-` ness to prevent the bodily rotation of the dial by means of theknurled flange 41. The preferable means which has been illustrated forrotating the pointer 27 by the longitudinal movement of-the measuringrod 11, comprises a bow spring 43, which is secured in place Within thecross-head 13, a flexible cord 44, preferably made of silk or the likematerial, interposed `between the outer end of the bow spring l43 andthe cross head 13 and secured to the latterby any approved fastening.means,as, for example, by a screw eye 45.l A knurled screw 46 isthreaded intoone side of the enlargement 3 of the ring 2, and whenscrewed down its inner end bears upon the measuring rod 11. lBy means ofthis screw, the rod may be secured in any given position, as, forexample, when a measurement is made in the dark, and the instrument maythen be removed bodily and the depth of the hole measured, or otherreading may be taken, where more light can be I obtained.

In the device shown in Fig. 5, the straight i edge and the graduatedsleeve are dispensed with andthe instrument is supported preferably fromthe back of the casing. I have shown it supported upon a rod 50 withrelation to which it may be angularly adjusted by means of screw 51. Therod 50 in turn is supported in a sleeve 52 rotatable upon a stud 53,which is in turn supported upon a sleeve 54, which last named sleeve maybe vertically adjusted and held by means of a screw 55 upon a standard56 whichris supported upon a base 57.l In this instance I have shown themeasuring rod 11 provided with a suitable bearing surface, such as therounded knob 58. It is evident that other points could be provided forthe rod 11 as desired.

When a device constructed in accordance with my invention is to be usedas a depth gage, as shown, for example, in Fig. 1, the straight edge 8is placed upon the object 59, when it 'is desired to measure the depthof the o ening therein. The clamping sleeve is then loosened and the jawsof the chuck 5 are placed in that groove of the sleeve 4corresponding most nearly to the depth of the opening 60.. The measuringrod -11 now rests upon the bottom of the said openingand is projectedthereby against the force of the spring 17 within the casing 1 and bythe operation of the cord 44, which is wound around the shaft 26 andheld'taut by the spring 43, the pointer 27 is turned upon the dial toindicate how much greater the depth of the opening 60 is, than is indi-In the device I have illustrated in Fig. 1, and wherein the normalprojection of the rod 11 is .2 of an inch, I have shown the dial 33divided into 200 equal parts, each of which, therefore, corresponds to.001 of an inch. The movement of the pointer 27 begins at thesub-division 200 and continues backward throughout the scale until ithas passed through an entire revolution. By this arrangement the amountwhich the measuring rod 11 extends from the end of the sleeve 4 may beread off directly from the scale, since at the beginning of its inwardmovement the measuring rod extends .2 of an inch beyond the end of thesaid sleeve and at the close of the said movement, when it has reachedthe zero point on the scale, it is flush with the end of the saidsleeve. If the distance to be measured does not exceed .2 of an inch,the sleeve 4 is fastened within the straight edge 8 by means of thechuck 5, so that the lower end of the said sleeve will be iush with thelower surface of the straight edge, the jaws 6 of the chuck engagingwith the groove which is shown in dotted lines in Fig. 1.

The device shown in Fig. 5, is used to determine the iatness oruniformity of one surface with respect to another. Both the article tobe tested, as the block shown at 61, and the gage supported upon thestand 57, being placed on a surface which is as nearly plane as can besecured, the gage and the object being then moved relatively to oneanother upon the said surface. When the device is used in this way it isdesirable that the dial may be rotated in order that the pointer may bemade to point initially to some particular sub-division on the dial, as,for example, the sub-division 100, and any deviation of any portion ofthe surface from this point may be then conveniently and accuratelydetermined.

Having described my invention, I claim- 1. In a measuring instrument,the combination of a dial casing, a measuring rod projecting therefrom,a spring to hold the rod projected and a resilient stop for limiting thedistance which the rod projects from the casing, a dial and pointer insaid casing and connections between said rod and said pointer such thatas the rod is caused to pro- Y memeso to indicate directly the amount ofprojection of the said rod beyond a fixed point, substantially as setforth.

3. In a measuring instrument, a casing, a measuring rod projectingtherefrom, a crosshead thereon within said casing, a spring acting onsaid cross-head to hold said rod projected, aj shaft having a pointerthereon, a bow spring supported by the cross-head, and a flexible cordinterposed between the said rod and the end of said bow spring andencircling the said shaft, substantially as set forth.

- 4. VIn apparatus of the class described, a dial casing having anannular seat therein and provided with a cover, a dial frictionallyretained in said seat and below said cover and having an outwardlyextended edge accessible from the exterior of the casing and cover,whereby said dial may be adjusted in its seat, and a movable pointer forsaid dial, substantially as described.

5. In a measuring instrument, the combination of a casing, a graduatedsleeve secured thereto, a measuring rod passing through the said sleeveand into the said casing and projected from the end of the said sleeve,a dial in the casing and means whereby the extent of projection of therod beyond the sleeve may be indicated upon the dial,

n substantially as setforth.

6. In a measuringinstrument, the combination of a cylindrlcal casing, agraduated sleeve secured thereto, a measuring rod passing throughy thesaid sleeve and into the casing and projecting beyond the end of thesaid sleeve, a dial in said casing, meanswhereby the extent ofprojection ofsaid rod may be indicated, on the dial, and means wherebythe rod maybe secured in any position, substantially as set forth. y

7. In a measuring instrument, the combination of a casing, a graduatedsleeve extending from the side thereof and provided with grooves at itspoints of sub-division, a straight edge slidable upon said sleeve andprovided with means for securing it to theV said sleeve at the saidgrooves,.a measuring rod projecting .beyond the end of the sleeve,extending therethrough and into the casing. a dial in said casing, andmeans whereby the amount of projection of the said rod may be indicatedupon the dial, substantially as set forth.

and passing therethrough and into the casing, a spring for holding thesaid rod projected, a resilient adjustable stop for limiting the extentof such projection, a dial in said casing, means whereby the extent ofthe projection of the said rod may be indicatedl upon the dial, andmeanswhereby the rod may be secured in any given position, substantially asset forth.

9. In a measuring instrument, a straight edge having a passage-waytherethrough, a graduated sleeve slidable in the -said passageway, meansfor positioning and securing the said sleeve fixedly in any of a numberof predetermined positions with respect to the said straight edge, ameasuring rod in the said sleeve and projecting beyond the end thereof,and means actuated by said rod and movable relative-v thereto forindicating directly the extent 1 t such projection, substantially as setforth.

10. In a measuring instrument, a straight edge, a graduated sleeveslidable therein, a

measuring rod within the sleeve coaxial therewith and spring pressed toextend normally'beyond one end thereof, and means located at the otherend of said sleeve and actuated by said rod for indicating directly theextent of such projection, said sleeve bea-ring indicia for indicatingits position, substantially as described.

11. In a measuring instrument, a` straight edge, a graduated sleeveslidable therein, a measuring rod slidable within the sleeve andspring-pressed to project one end'normally beyond one end of sa1d sleeveto a prede-k

